gravitational lensing

James Webb Space Telescope Uncovers the Dwarf Galaxy Powerhouses of the Early Universe

Astronomers using the James Webb Space Telescope have identified numerous dwarf galaxies that existed when the universe was merely 800 million years old. These galaxies played a pivotal role during the reionization epoch by emitting significant ultraviolet radiation, which helped clear the universe's hydrogen fog. Observing the Abell 2744 galaxy cluster, which serves as a gravitational lens, the study challenges the former assumption that larger galaxies were the primary drivers of this cosmic event.